This invention has to do with vibration testing of test pieces in temperature-controlled environments. More particularly, the invention has to do with improvements in slip plate assemblies for use in vibration testing of test pieces in extreme temperature thermal cycling closed environments.
Vibration testing is a now accepted procedure for evaluating the mechanical dependability of numerous pieces of equipment, especially those intended for military and space use. Devices of a mechanical, electromechanical and electronic nature are subjected to a controlled shaking in carefully prescribed tests to evaluate their use life and their use dependability. Typically, these evaluations have been carried out at room temperature or other similar ambient temperature, e.g. 72.degree. F. It is nonetheless true that many of the devices being tested are subjected to vibration, e.g. in carriage aboard an aircraft at dramatically different temperature extremes. Thus, a fighter airplane may sit on the desert floor for substantial periods of time exposed to a searing heat, only to be followed by a scramble exercise which carries the aircraft to extremely high altitudes in a very brief period of time. The high altitude temperatures, of course, are far below 0.degree. F. Equipment aboard the aircraft, for example gun control equipment, is thus subjected to a thermal cycling between searing desert heat and sub-freezing high altitude temperatures, all in a short space of time and all to the accompaniment of a relentless vibration.
Accordingly, there is a need to assess the dependability characteristics of equipment, not only as to its vibration-resistance capabilities at ambient temperatures, but also during thermal cycling which simulates the actual use environment. For this purpose, there have been developed controlled temperature closed environments for shrouding the test piece during vibration testing. Such shrouds are essentially chambers which totally enclose the test piece in a manner providing the desired temperature condition, or series of temperature conditions in the case of thermal cycling, established for effective testing of the device.